Motor control.



A. SUNDH.

MOTOR CONTROL,

APPLlOATION FILED MARJB, 1908.

1,01 1,267, Patented De0.12,1911.

citizen of the United States,

UNITE STATES PATENT OFFICE.

ASSIGNOR TO OTIS ELEVATOR COMPANY, OF

CORPORATION OF NEW JERSEY.

MOTOR CONTROL.

Specification of Letters Patent.

Patented Dec. 12, 1911.

Application filed March 13, 1908. Serial No. 420,832.

T all whom it may concern:

Be it knownthat I, AUoUs'r SUNDH, a residing in Yonkers, in the county of lVestchester and State of New York,

of which the following is a specification.

My invention relates to motor controlling apparatus, and, although herein shown a", plied to an elevator system, it may have a general application.

One of the'objects of my invention is the provision of simple and efficient means for starting, operating and stopping an electric motor.

The specific objects of the invention will appear hereinafter, the novel combinations of elements being set forth in the appended claims.

In the accompanying drawings, Figure 1 represents an elevator system with my in-' vention applied thereto; Fig. 2 is a detail of the switches for controlling the reversing switch magnets; Figs. 3 and 1 are side elevational views of the two portions of the reversing switch apparatus for the motor;

and Fig. 5 is a fragmentary side view of in mesh with the worm wheel 7 mounted to the eccentric cam for transmitting motion to the pilot valve of the fluid pressure controlling apparatus.

Referring to Fig. vator car, H the 1, C designates an ele hoisting drum, and W the counterweight. A hoisting cable or cables 1 extends from the top of the car C over the overhead sheave 2 to the hoisting drum H. A counterweight cable 31s connected to the counterweight \V and extends over the sheave t to the drum Ht. Thesheaves 2 and 4 are journaled in fixed hearings in the stationary overhead b'an mol l1 designates an electric motor-,which in this instance is of the-direct current shunt wound type. The shaft (3 of this motor is connected to a worm rotate with the drum H so to transmit motion thereto when the motor M receives current. An elevator system of any other type than that illustrated may be used if desired.

In the elevator shaft is a standing rope 8 connected at its upper ends 9, 10 to fixed points, such as the overhead beam 5, the lower loop being in frictional contact with have invented a new i and useful Improvement 1n Motor Control, I

the pulley 11 and the intermediate portions of this rope being associated with the pul leys of the manual actuating apparatus comprising the lever 12 in the car. When the lever 12 is moved in one direction, motion is transmitted to the pulley 11 in a corresponding direction; and when the lever 12 is moved in the opposite direction, the pulley 11 will also be moved. in the opposite direction. Connected to rotate with the pulley 11 is a bevel gear wheel 13 which is in mesh with. another bevel gear 1 1 on the shaft 15. The latter shaft has also a spur ear 16 which is in mesh with the spur gear 17, the latter being connected to the shaft 18 to transmit rotative movement thereto. The latter shaft is mounted in the bearings 19, 19 and carries the cam 20, the cams 21, 21 and the eccentric cam 22. The cam 20 is shown in end View in Fig. 2. The cams 21 and 21 are shown in side view in Figs 3 and 1-. And the eccentric cam 22 is shown in'detail in Fig. 5. Now, when the lever 12 is moved to the right, for instance, the pulley 11 will be moved clockwise and transmit rotative movement to the shaft 18 in an anti-clockwise direction when looked at from the right in Fig. 1. The cam 20 shown in Fig. 2 will therefore'be'moved in an anticlockwise direotion to move the lever 23 on the pivot 24 against the action of the springs 25 and 26 to close the switch 27. A circuit will therefore be closed from the main a through the blade 28 of the main line switch 29, thence through the conduc ors 30, 31, switch 27, conductor 32, solenoid 33, conductor 34, conductor 35, blade 36, to the other main b. The main conductors a and b are connected to any suitable source of current supply.

It will be observed that the cams 21, 21 on the shaft 18 initially press against the rollers 87, 37 to hold the switches it, it in their initial positions as indicated in Fig. 1. When, however, the shaft 18 is rotated in an anti-clockwise direction in the manner indicated, the roller 37 will be released by the cam 21 to permit the magnet 38 to move upwardly the stem. 39 to close the switch B. At. this time the cam 21 still holds the switch it in its initial. position. If the le l ver 12 in the car is moved to the left, then 1 clockwise rotation is transmitted to the the magnet 38 nails 90, 90.

shaft 18 and the switch-27 is closed, and

energized. to effect the closure of the switch it. In the latter case, the cam 21 being rotated in an opposite direction will hold the switch R open.

When the switch it is closed, a circuit will be closed through the motor M as' follows fronr the main a, through blade 28, conductors 36, 40, series held of the motor, conductor 41, sectional starting resistance 42, resistancewarying member 43, contact 44, conductor 45, switch R,conductor 46, armature brush 47, the armature windings, armature brush 48, conductor 49, blade of the switch R, switch R, conductor 51, blade 36, to the other lead or main Z9. Atthe same time that the switch it is closed, the brake magnet 52 is connected across the mains by the conductors 53 and 54 to release the brake apparatus applied to the brake pulley on the motor shaft 6. At the same time that a circuit is closed through the brake magnet 52, a circuit is also closed through the shunt field windings of the motor M through the conductors 53, 89, and the shunt field termielectric motor nowreceivlng power and having all. the starting resistance 42 in circuit therewith, may rotate at slow speed and transmit motion to the car O through the intermediate mechanism.

011 the shaft 6 are two eccentric devices 55. 55 for transmitting reciprocatory motion to the connecting rods 56, 56 and the pistons 57, 57 of the fluid compressor 58. In this instance this compressor comprises the pistons 57, 57 fitting into the open ended chambers 59, 59'. Suitable checkvalves are arranged in this compressor to effect the transmission of air through the duct or pipe 60 to the chamber 61 in which fits the piston 62 of the motor accelerating apparatus. In this instance when the piston 57 is moved to the right, air is drawn into the chamber 59 through the check valve 63 against the action of the spring 64, the check valve65 being at this time closed. At the same time that the piston 57 moves to the right, the piston 57 moves to the left and. forces air from the chamber- 59 throu h the check valve 65. When the piston 57 is moved to the left, the check valve 63 automatically closes and air-is forced from the chamber 59 past the check, valve 65 into the pipe 60. Therefore as soon as the motor starts, the compressor is operated to force air from the pipe 60 to the chamber 61. The flow of this.

air from the pipe 60 to the chamber 61 is controlled by the pilot valve '66 which has a transverse passage 67 initially in the position shown in Fig. 1 when communicationbetween the pipe 60 and the chamber 61 is cut oil". Vl hether the lever inthe car, and consequently the shaft 18, ismoved. in one direction or the other, the eccentric cam 22 would transmit downward motion to the rod 68 .against the action of the spring 69.

The rod 69 is extended at its lower end into I a rack 70, and the said rod is guided through a bracket 71 extending from the casting 72 in which the chamber 61 is formed. The rack is in mesh with the gear wheel 73 which is connected by links and levers 74 to the pilot valve 66 and to an additional gear wheel 75. The latter is in mesh with the rack 76 extending from a valve has'been actuated'manually from the car through mechanicalconnections, and the motor starts, the compressor 50 will pump air intothe chamber 61 to force the piston 62 to the right against the action of the spring 78. The piston 62 being connected by the rod 79 to the resistance vary ing member 43, will transmit motion to the latter to move the same over the seriesof contacts 88 which are connected to sections of the starting resistance 42 and to the. 'se-' ries field of the motor. In anobvious manner, as the resistance varying member 43 moves to'the right over the contacts 81, the starting resistance will be gradually cut out,

member 43 engages the contact 88. The motor may then operate at full speed as. a shunt wound motor. I

It will be observed that as the piston 62 moves to the right, the rack 76 will rotate the gear 75 in an; anti-clockwise direction and thereby effect the restoration of the valve 66 back to its initial posit-ion as shown in Fig. 1. The arrangement may be such. that upon comparatively small movement of the lever 12, the cam 20 and the cam 21 or 21 will be operated to effect the starting of the motor at once, and, upon further movement of the lever in the car to various posltions the cam 22 WlllbQIIIOVGCl to corresponding positions to effect successive op and finally also the series field when the eration of the valve 66 to secure' further movement of the member 48 or to hold the same in any intermediate position desired. This will be clear when it is observed that the larger portions of the cams 20, 21 and 21 are concentric as to the shaft whichcarries them. \Vh'en the valve 66 cuts off communication between the pipe 60 and the chamber 61 while the motor is still operating the compressor 58, the pressure'm the pipe 60 will increase to such a value that the check valve 91 will open automatically to let the air into the pipe92, through which it is transmitted to'the pipe 93 and thence to the series of nozzles 97 which are so 211'- ranged as to blow out any arcs which may form while the resistance-varying member 43 is moving from one contact to another of the contacts 88. Air is also forced through the branch pipe 94 to the nozzles 95 for the reversing switches R, It; and the nozzle 96 for the switches 27, 27. An additional. function of the arrangement for directing air under pressure to the contacts of the switches is to keep them cool and free from dust or other matter. The principal utility of the branch pipes leading from the check valve 91 to the nozzles mentioned, is to direct currents of air over the contacts of the switches when the latter are being opened or restored to initial position. For instance, when the lever 12 in the car is brought back to its central or neutral posi tion, the cam. 22 will be correspondingly moved to its initial position to permit the spring (59 to move the v rack 70 upwardly, which will transmit motion to the valve 60 to move the same to the left and establish con'miunication between the chamber 61 and the pipe 92. The spring 7 8 will therefore at once act to force the air in the chamber 61 through the pipes 92, 94 to the nozzles 95 and 96, and through the pipe 93 to the nozzles 97. Therefore, while the current is being cut oil from the motor and it is com-- ing to rest, all arcs are blown out where switch contacts are being separated. Owing to the escape of air through'the nozzles 95, 96 and 97 the pressure of air in the'pipe 92 is at this time insufficient to compress the spring 78 or prevent it from moving" the piston 62 to its innermost position. When the piston 62 is moved to the left, the gear 75 is rotated clockwise to move the valve 66 back toits closed position as indicated in Fig ,1.

, It will be observed that after the motor starts it must run a short period of time before the air in the pipe 60 and chamber 61 is compressed sufficiently to move the piston 62 against the action of the spring78.

The rate of movement of the piston 62 after. the motor starts will depend upon the ca pacity oftlie compressor 58 and the resist-- ance ciferedby the spring 7-8. This spring may be so constructed that the resistance thereof is increased as it is compressed, and, in any event, under given conditions of load, etc., it will be a predetermined length of time after current is applied to themotor' for the resistance-varying member 43 to move to its extreme right-hand position or any selected intermediate position to effecta g *adual acceleration of the motor to full speed or an intermediate speed. As before explained, the speed of the motor will do pend upon' the position of the lever 12 in the car, or more directly upon the position of the cam 22.

Although l have shown a direct current 3. The.

shunt wound motor, which is considered the most practicable. for the operation of ele vators where direct current is available, it should be understood that an alternating current motor, such as a three-phase induc tion motor, may be used where only alternating current is available. .ltn such event the apparatus may be so arranged as to out in and out sections of windings of a trr sfcrmer to vary the applied voltage, or st ing resistance may be controlled.

Obviously those skilled in the art. make various changes in. the details an rangenient of parts without departing the spirit and scope of my invent-ion, l I desire thereforc'not to be limit-ed to the precise construction herein. disclosed.

tion, what I claim and seek to have protected by Letters Patent of the United States is r i 1. The combination with an electric motor, of accelerating mechanism therefor, apparatus for propelling fluid to actuate said accelerating mechanism in proportion to the speed of said motor, mechanical applianoes for controlling the flow of fluid, and manual mechanical means for operat ,ing said mechanical controlling appliances.

2. The combination with a motor, of two sources of power, one being ele tric and the other being fluid pressure and in strength proportional to the speed of said motor, means operated by said electric power for starting said motor, appliances operated by said fluid pressure for accelerating the motor, mechanical controlling mechanism, and manual means for operating said controlling mechanism.

combination "with motor, of a fluid actuator driven only when said motor operates, starting switches for said motor, electric .means for operating said starting switches, a mechanical device for closing the circuits to said; starting switches, manual mechanism for actuating said mechanical device, and means operated by the fluid actuator for controlling the acceleration of said motor.

4'. The combination with an electric motor, of reversing switches therefor, electric means for operating said switches, and cam mechanism for actuating said switches to positively restore the same to normal position after every operation thereof,

5. The combination with an electric m0- tor, of reversing switches therefor, electric means for closing said switches, and cam mechanism for positively actuating a partof said switches to open the same after every operation thereof.

(3. The combination with. an electric motor, of reversing switches therefor, mechanical appliances for normally holding both of said switches in open position, means for an electric ines lease one of said switches,'and electric de vices for closing said switches.

7. lhe combination with an electric mo-' tor, of a reversing switch therefor, electric means for operating said switch, and mechanism for positively actuating parts of said switch o move the same and hold the .entire switch in open position after every operation thereof.

8. The combination with an electric motor, of reversing switches therefor, an electro-magnetic operating device for each of said switches, an actuator for each switch to positively move the same to open position and to hold said switch normally in open position, and means for operating said actuator to effect the release of one of said switches and permit the same to be closed.

9. The combination with an electric niotor, of reversing switches therefor, an electro magnet for each switch'to operate the same, cam mechanism for positively'moving said switches to open position, and manually operated mechanical appliances for actuating said cam mechanism.

10. The combination with an electric mtor, of reversing switches therefor, electric means for closing said switches, a plurality of cams, a shaft carrying said cams, connections between said cams and switches, and mechanism for actuating said shaft to release one of switches or to positively move a closed switch to open position.

11. The combination with an electric motor, of reversing switches therefor, accelerat ing apparatus and means for operating the 'ne, ai. i'1'"ll"/ devices closing said es, appl nces for normally holding es in open position, single for eiiecting the operation of atrng apparatus and mechann 1 ingsaid appliances. ihe COll'tJli'lzl'tlOIi with an electric'motor, of star ing appara us, fluid-compressor, a device actuated by liuid pressure to operate said accelerating apparatus, a valve for con ,rol ling connminication between the fluid-compressor and said operating device, branch or ducts having nozzles at their ends near the contacts of said switches and :rating apparatus, and a check .valve the fluidcompressor and such 5 patent may obtained for ing switches therefor, accelerat of fluid into said device to effect the actuation thereof or to control the exhaust of Li ui d from said device through said branch pipes or ducts.-

14-. 'l. he combination with an electric m0- tor, of reversing switch mechanism therefor, accelerating apparatus, an air pump operated by the motor, a motor device operated by air pressure to effect the operation of the accelerating apparatus, a pipe or duct between the air pump and said motor device, branch pipes having nozzles at their ends at or near the switch contacts of the revers ng switch mechanism and accelerating apparatus, a? check valve between the first-named pipe or duct and the branch pipes and opening from the former to the latter, and a pilot valve forv controlling communication between the air pump and the motor device and between the latter and the branch pipes.

switches to normal position after every operation thereof.

16. The combination with an electric motor, of reversing switches therefor, electric means "for operating the switches, and mechanical means for positively restoring said switches to normal position after every operation thereof.

17. The con' bination with an electric motor, of reversing switches therefor, means for operating the switches, and cam mechanism for positively restoring said switches to normal position after every operation thereof.

18. The combination with an electric motor, of reversing switchestherefor, electric means for operating said switches, and means operable from a distance for positively restoring said switches to nonnal position after each operation. thereof.

19. The combination with an electric motor, of reversing switches therefor, electric means for operating said switches, and manually operable means for positively restoring said switches to normal position after each operation thereof.

20. The combination with an electric motor, of reversing switches therefor, electric means for operating said switches to closed position, and manually operable means for positively effecting an openmg of said switches at any time.

ln testimony whereof, I have si ned my namcto this specification in the presence of two subscribing witnesses.

AUGUST SUNDH. l l itnesses i W. El. BRADY, Gin-as. M. Nissan,

' cents each, by addressing the commissioner of." ingtcn, 3. 

